Operating mechanism and interlock for enclosed switches



Aug. 21, 1956 2,760,021

OPERATING MECHANISM AND INTERLOCK- FOR ENCLOSED SWITCHES T. M. COLE ET AL Filed Feb. 17.

4 Sheets-Sheet l S R m w m THOMAS M. COL/f WND PAUL /I CH/F/STENSE/V BY m na-0&1- NM QTL Aug. 21, 1956 T. M. COLE ETAL 2,760,021

OPERATING MECHANISM AND INTERLOCK FOR ENCLOSED SWITCHES Filed Feb. 17, 19so 4 Sheds-Sheet? FlE- INVENTORS. THOMAS M. 0045 M 1 7T TORNE Y6 Aug. 21, 1956 T. M. COLE ETAL 2,760,021

OPERATING MECHANISM AND INTERLOCK FOR ENCLOSED SWITCHES med Feb. 17. 1950 4 Sheets-Shed 3 FHEJE IN VEN TORS THOMAS M, COLE mvo PAUL M. CHR/STEA/SEN WWW F C042 ATTORNEYS Aug. 21,1956 T. M. COLE ETAL 2,760,021

OPERATING MECHANISM AND INTERLOCK FOR ENCLOSED SWITCHES Filed Feb. 17, 1950 4 sheets-sheep:

' THOMAS M. c045 m I63 PAUL M. C/v'fi/STE/VSEN 02, By F llv I c Q FEQJZ 1 IN V EN TORS.

tates UPERATING MECHANISM AND KNTERLOCK FOR ENCLGSED SWITCHES Thomas M. Cole New York, N. Y., and Paul M. Christen sen, West Orange, N. 31, assignors to Federal Electric Products Company, Newark, N. J., a corporation Application February 17, 1950, Serial No. 144,636 17 Claims. (Cl. 2011-50) an interlock mechanism which, with the switch-operating handle locked in switch 011 position, positively prevents the opening of the switch enclosure cover and thereby prevents the closing of the switch operating mechanism.

Another object is the provision of interlock mechanism which normally prevents the switch enclosure cover being opened when the switch-operating mechanism is in switch off position.

Another object is the provision of switch-operating mechanism which cannot be readily operated when the switch enclosure cover is open.

Another object is the provision of interlocking mechanism which, in the switch on position of the switchoperating mechanism, permits the switch-enclosure cover to be opened without moving the switch-operating handle from the on position and without moving the switchoperating mechanism from the on position.

The above and other objects, features and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a perspective view of an enclosed switch embodying the present invention;

Fig. 2 is a perspective view showing the casing cover open;

Fig. 3 is a sectional view on the line 3-3 of Fig. 1, the switch-operating mechanism being shown in 01f position;

Fig. 4 is a view similar to Fig. 3 showing the switchoperating mechanism in on position;

Fig. 5 is a sectional view on the line 5-5 of Fig.

Fig. 6 is a sectional view on the line 6-6 of Fig.

Fig. 7 is a sectional view on the line 7-7 of Fig.

Fig. 8 is a sectional view on the line 8-8 of Fig.

Fig. 9 is a sectional view on the line 9-9 of Fig.

Fig. 10 is a view, in elevation, of the switch-operating mechanism;

Fig. 11 is a view similar to Fig. 10 with a part removed;

Fig. 12 is a sectional view on the line 12-12 of Fig. 10;

Fig. 13 is a fragmentary view of the inner surface of the cover showing the interlock thereon in locking position;

Fig. 14 is a view similar to Fig. 13 showing the interlock in releasing position; and

Fig. 15 is a sectional view on the line 15-15 of Fig. 4.

Referring now to the drawings in detail, the switchoperating mechanism 10 of the present invention is shown mounted in the box 12 of the switch casing or enclosure 14 for causing the engagement and disengagement of the separable contacts of a suitable switch or circuit breaker (not shown). Said box 12 is provided with a cover 16 2,760,021 Patented Aug. 21, 1956 ICC which is hinged at one side thereof, as indicated at 18, so that said cover may be swung to closed and open positions, as illustrated in Figs. 1 and 2.

A switch-operating handle 20 is mounted for turning movement on cover 16, externally of the latter. Said handle is preferably of the type illustrated and described in the copending application of Egmont Arens, Serial No. 75,652, filed February 10, 1949, now United States Patent No. 2,672,746, dated March 23, 1954, and assigned to the assignee hereof. As is fully illustrated and described in said application, and as here shown, the hub portion 22 of handle 20 registers with an opening in the cover 16, a disk 24 being disposed at the inner surface of said cover and beiiig connected to said hub by screws 26, said handle being provided with a rectilinearly movable locking member 28 slidably movable in a slot 30 of the handle from a retracted or handle-releasing position, as here shown, to a projected or handle-locking position, as shown in said application. As further illustrated and described in said application, locking member 28 has an elongated opening which is disposed internally of the handle hub 22 when the locking member is in said retracted position, and which is disposed externally of the handle in said projected handle-locking position, a removable lock disposed in said opening serving to hold said locking member in its handle-locking position. As here shown, the handle is movable through to and from its on and 011? positions, illustrated in Figs. 4 and 3, respectively, and can be locked by the locking member 28 in either of said positions.

The cover 16 may be locked closed by one or more devices well known to those skilled in the art. One such device may comprise the conventional pivoted cover latch 32 carried by the switch box 12 and engageable in an opening 34 of the cover, said latch being provided with an opening 36 for a lock. In addition, an interlock de vice 38, hereinafter fully described, is provided on the switch-operating mechanism 10 for absolutely preventing the opening of the cover in the locked 01f position of the handle and for normally preventing the opening of the cover in both the off and on positions of said mechanism.

As illustrated and described in said copending application, and as here shown, the switch-operating handle 20 is operatively connected to the lever 40 (Fig. 2). Said lever is pivotally mounted at one end thereof to a bracket 42 in any suitable way, as by a pivot stud or shouldered screw 44, said bracket being welded or otherwise secured to the inner side of the cover. The disk 24 is connected to the lever 40 by a link 46 which is pivotally connected at its opposite ends to said lever, intermediate the opposite ends of the latter, and to a radially projecting lug or ear 48 in disk 24, by means of the pivot studs 50 and 52, respectively. An ofiset end portion or extension 54 of the handle operated lever 40 releasably engages the switch-operating mechanism 10, as will presently appear, for operating or actuating the latter to open and close the switch.

Pursuant to one feature of the present invention, the casing cover 16 is provided with an interlock release element or locking member 56 (Figs. 2, 3, 4, 6, 13, 14) mounted for turning movement on the inner surface of said cover and which extends inwardly of the casing. More particularly, interlock release 56 is provided with the opposing end portions 58 and 69 which are normal to the central portion 62 and which extend in opposite directions therefrom, as illustrated in Fig. 2, said portion 58 being provided with an inwardly inclined latch element 64. Interlock release 56 is operated by a screwheaded stud 66 which is mounted for rotation in cover 16 and which is suitably secured to end portion 60, as

at 68. It will be understood that the rotation of stud 66 on the outer surface of the cover causes interlock release 56 to turn on the inner surface of the cover about the axis of said stud. The interlock release is biased into its normal locking position (Fig. 13) by the tension spring 70, one end of which is secured in portion 62 of the interlock and the other end of which is secured in the extending portion 72 of a stop member 74 secured to the inner surface of the cover. As illustrated in Fig. 13, spring biases the interlock release for rotation in a clockwise direction (viewing the inner surface of the cover), said rotation being limited by the abutment of side edge 76 of the interlock against the stop member. Rotation of the interlock release in the opposite or unlocking direction by stud 66, against the bias of spring 70, is limited by the engagement of corner portion 78 of the interlock release against side edge 80 of the stop member, and by the engagement of corner portion 82 of the stop member against side edge 76 of the interlock release, as illustrated in Fig. 14.

The switch-operating mechanism 10 of the present invention is disposed in the box 14 for moving a bail or shaft 84 to open and close the separable contacts of a switch (not shown) which is carried by a mounting plate 86 secured by screws 88 to the inner surface of the back wall or pan 90 of the casing. The switch may be of the construction shown in the application of Paul M. Christensen, Serial No. 75,637 filed February 10, 1949, now United States Patent No. 2,689,291, dated September 14, 1954, and assigned to the assignee of our present application. As here shown, the bail or shaft 84 comprises a metallic rod 92 (Fig. 8) having an insulating covering 94 and provided with the spaced arms 96 and 98 at the ends thereof. Arm 96 is mounted for pivotal movement about a pivot stud 100 carried by a pivot plate 102 secured to pan 86, adjacent the side edge 184 thereof, by screws 106 and which extends upwardly therefrom. Arm 98 is mounted for pivotal movement about a pivot stud 107 carried by the switch-operating mechanism 10 and is provided with a struck-out portion 108 which is engaged in said mechanism for movement thereby to effect the pivotal movement of the bail about an axis extending between said pivot studs 100 and 107, as will presently appear.

The switch-operating mechanism comprises the mounting plate 110 on which is pivotally mounted a drive lever or actuator 112 and a crank arm 114. Mounting plate 110 is secured to plate 86 adjacent the edge 116 thereof opposite edge 104. Said plate 110 has an inturned portion 118 provided with a rectangular slot 120 (Fig. 9), a struck-up guide portion 122 of plate 86 extending through said slot, and said inturned portion being secured to plate 86 by screws 124 whereby the plate 111) is mounted in opposition to plate 102.

The aforementioned pivot stud 107 is carried by plate 110 and has a pivot portion 126 extending from one side of said plate toward the interior of the casing in alignment with pivot stud 100, the bail arm 98 being pivotally engaged on said pivot portion. Said pivot stud 107 is provided, on the other side of the plate, with a head 128 and with a collar portion 130 of lesser diameter than said head but of greater diameter than said portion.

The crank-arm 114 is mounted for pivotal movement on the collar 130, being disposed between head 128 and plate 110. Said crank-am is provided with a narrowed portion 1332 (Figs. 5 and 11) having an elongated aperture 134 through which is disposed a pivot stud 136 on which a toggle arm 138 is mounted for pivotal movement. Said toggle arm 138 is provided with an axially extending portion 140 of reduced width, the free end 142 of which extends through a slot 144 defined in an ear 146 provided on the plate 110, said arm being slidably movable in the slot and said ear extending in a direction outwardly of the casing. A helical compression spring 148 is mounted on said portion 140, one end thereof engaging said ear and the other end engaging the shoulders 150 of said toggle arm 138. It will be understood that crank-arm 114 and said arm 138, provided with spring 1 10 together comprise a spring toggle mechanism with a snap action in opposite directions. The disposition of said toggle in the off position of the switch-operating mechanism is illustrated in Figs. 3, l0 and 11, the disposition of the toggle mechanism in the on position being illustrated in Fig. 4.

Referring now to Fig. 11, it will be apparent that when the toggle joint formed at pivot stud 136, is carried beyond the toggle center-line extending between pivot stud 107 and slot 144 in car 146, the action of the spring 148 will snap the toggle mechanism to the position illustrated in Fig. 4. Similarly, when the toggle joint is overcentered from the position shown in Fig. 4, it will be snapped back to the position illustrated in Figs. 3 and 11. The outwardly bent portion 152 (Fig. 5) of plate 110 provides a detent or stop to limit the travel of the toggle mechanism in its off position and a similar portion 154 limits the travel of the toggle mechanism in its on position.

In order to effect the aforementioned pivotal movement of the bail, the crank arm is provided with an arcuate slotted portion 156 in which the struck-out part 188 of bail arm 98 is engaged, said part extending through the opening 158 in plate 110. It will be apparent that during the movement of the toggle mechanism to and from the on and off positions thereof, the bail is carried by the crank arm and pivots about the companion pivot studs 100 and 107.

Operative engagement between the handle operated lever 41) and the crank-arm for the operation of the toggle mechanism is effected through the drive lever 112. Said drive lever is mounted for pivotal movement on a pivot stud 169 extending outwardly from plate 118. Said pivot stud is in longitudinal alignment with the pivot stud 107, being positioned therebelow. Pivot stud 160 is provided with a portion 162 (Fig. 9) of larger diameter on which is disposed a coil spring 164, the drive lever being mounted on a portion 166 of reduced diameter and being retained therein by a cotter pin 168 positioned in the peripheral groove 170. One end of the spring is engaged in a notch 172 in the drive lever and the other end is engaged in the corner 174 (Fig. 9) formed in plate 118 by the portion 118 thereof whereby the drive lever is biased in a clockwise direction. viewing Fig. 10. The drive lever is provided with an aperture 176 in which there is engaged the part 178 (Fig. 7) extending from the crank-arm for the operation of the toggle mechanism upon the movement of the drive lever by the handlc operated lever 40, as will presently appear. The drive lever is retained against outward displacement relative to plate 110 by a struck-out portion 180 thereof which overlies an arcuate peripheral portion 182 of said plate and which is turned down at 184 (Fig. l2) to prevent said displacement. The shoulders 186 and 188 (Fig. 11) formed in plate 110 at the ends of said peripheral portion 182, serve as detents or stops for the drive lever, shoulder 186 being engaged by portion 180 when the toggle mechanism moves to the on position, and shoulder 188 being engaged by portion 180 when the toggle mechanism moves to the off position. The drive lever is also provided with offset portions 190, 192 (Fig. 6), between which said portion 180 extends. Each of said offset portions is provided with a struck-out portion 194 which is adapted for the insertion of a suitable tool, such as a screw-driver, for manual operation of the drive lever when the cover is open. This is advantageous for checking the operation of the switch-operating mechanism for maintenance and repair purposes. It will be understood that the tension of toggle spring 148 is such that the drive lever cannot normally be operated by hand, with cover 16 open, unless said tool is used.

To effect the pivotal movement of drive lever 112 about pivot pin 160 for overcentering the toggle mechanism when the cover is closed, the previously mentioned offset portion 54, of handle lever 40, is disposed above the struck-out portion 180 of said drive lever and between the opposing edges 196 and 198 of the offset portions 190 and 192, respectively, of the drive lever. In closing the switch operating mechanism to on position, the handle is turned from the position illustrated in Figs. 1 and 3 to the position illustrated in Fig. 4. During said movement the offset portion 5 engages edge 196 of offset drive lever part 190 and pivots said drive lever about pivot pin 160 in a counter-clockwise direction, viewing Fig. 3. The crank lever 114, having its part 178 in engagement with the drive lever, is moved thereby in the same direction until the toggle mechanism is overcentered and snaps into the position illustrated in Fig. 4,

the handle 20 having been turned substantially 90". In opening the switch, the handle is turned from its position in Fig. 4 to its position in Fig. 3, and during this movement the offset portion 54 thereof engages edge 1% of part 192 to pivot the drive lever in the opposite direction thereby operating the toggle in the opposite direction to the off position. It will be noted that the drive lever and the toggle move in parallel planes. As previously described, the operation of the toggle in each direction effects the pivotal movement of the bail to the on and 01f positions of the switch, said movement being transverse to said parallel planes. It will be noted that since the bail and the drive lever pivot on different centers, only a small throw, substantially 90 degrees, of the switch handle is required to close and open the switch.

To provide interlocking means for the switch of the present invention, the aforementioned interlock or latch member 38 and release 56 are provided. Member 38 is an elongated element having an elongated slotted portion 202 through which there extends the pivot stud (Fig. 6) 204 secured in plate 110 and extending inwardly thereof, said stud being provided with a collar 266 on which member 38 pivots, and with a head 2% for retaining the latter on the collar. At one end thereof, the member 38 is provided with an angularly extending portion 210 (Fig. 7) which extends through an aperture 212 in plate 110. Said portion 210 is engaged by an extending part 214 (Fig. 11) of the crank-arm 114, a sear spring 216 carried on pivot stud 2G4 and disposed between member 38 and plate 110, biasing said portion 210 to engage said part 214. One end of the spring is engaged in an aperture 218 in member 33, the other end being engaged in an aperture 220 in plate 11f). At its other end, member 38 is provided with the oppositely extending latch portions or wings 222 and 224. Fig. 3 illustrates the position of member 33 in the off position of the switch, part 21.4 of the crank arm serving as a detent to limit the movement of member 38, as illustrated in Fig. 7. It will be noted that latch portion 222 is positioned be tween the cover and offset portion 54 of handle lever it to intercept portion 54 to prevent the opening of the cover by merely pulling outwardly on the handle. In order to open the cover, in said off position, it is necessary to turn the handle slightly, in the direction of the on position thereof to a cover open position which is within the range of said off position, as at 226 in Fig. 1, in which said portion 54 clears said offset portion. To positively lock the switch-operating mechanism in the off position, the handle can be padlocked in its 013? position, as described, to prevent the turning thereof necessary for offset 54 to clear latch 222. This prevents the cover from being opened and thereby prevents direct hand operation of the switch-operating mechanism.

In the on position illustrated in Fig. 4, it will be noted that member 38 has been pivoted so that the latch portion 224 thereof is interposed between the latch portion 64 of interlock device 56 and the front cover. Member 38 is biased into said latter position by spring 216, it being noted that this results from the fact that the retaining portion 214 of the crank arm moves to the position illustrated in Fig. 4 in the on position to permit mem ber 38 to be pivoted to the position illustrated therein, by said spring. It will be apparent that if the handle is pulled outwardly latch 64 will be intercepted by latch 224 to prevent the opening of the cover in the on position. However, if interlock release 56 is rotated by screw 66, as in Fig. 14, latch 64 will be clear of latch 224 and the cover will open permitting the inspection of the switch-operating mechanism in its on position.

While We have shown and described the preferred embodiments of our invention, it will be understood that various changes may be made in the present invention without departing from the underlying idea or principles of the invention within the scope of the appended claims.

Having thus described our invention, what we claim and desire to secure by Letters Patent, is:

l. in a switch casing having an openable cover, a handle mounted for turning movement on said cover to off and on positions and a member movably mounted in said casing for actuating a switch disposed therein, mechanism operable by said handle for moving said member comprising a plate fixedly mounted in said casing, drive means operatively connected to said handle and mounted for pivotal movement on said plate in a plane transverse the path of movement of said member, toggle means mounted on said plate for movement in opposite directions in a plane parallel to said plane of movement of said drive means, said toggle means including a crank operated by said drive means for overcentering said toggle means, and means interengaging said toggle means and said member for moving said member upon the operation of said toggle means, and interlock means carried by said mechanism and said cover for locking said cover in each of said positions, said interlock means including a latch member biased for movement to a first locking position and movable by said crank to a second locking position in response to predetermined movement of said handle.

2. in a switch casing having an openable cover, a handle mounted for turning movement on said cover to off and on positions and a member movably mounted in said casing for actuating a switch disposed therein, mechanism operable by said handle for moving said member comprising a plate fixedly mounted in said casing, drive means operatively connected to said handle and mounted for pivotal movement on said plate, toggle means mounted on said plate for movement in opposite directions, said drive means and said toggle means being interengaged for op-- erating the latter means upon movement of the former means, and means interengaging said toggle means and said member for moving said member upon the operation of said toggle means, and interlock means carried by said mechanism and said cover for locking said cover in each of said positions, said interlock means comprising a latch member mounted on said plate and biased into engagement with said toggle means for pivotal movement upon the operation thereof, a part operatively connected to said handle and engageable with said drive means for operating the latter, and a release part carried by said cover and movable relative thereto, said latch member being movable between said parts and being disposed between said handle-part and said cover in one of said handle positions for intercepting said handle-part to prevent the opening of the cover in said one position, and said latch member being disposed between said release part and the cover in the other of said handle positions for intercepting said release part to prevent the opening of the cover in said other position.

3. In a switch casing having an operable cover and provided with an operating handle mounted for movement on said cover and having a member movably mounted in said casing for actuating a switch disposed within the casing, mechanism operable by said handle for moving said member comprising a plate fixedly mounted in said casing, said plate being mounted on the rear wall of said casing and extending toward said cover in substantially parallel disposition with the side walls of said casing, drive means operatively connected to said handle and mounted for pivotal movement on said plate in a plane transverse the path of movement of said member, toggle means mounted on said plate for movement in opposite directions in a plane parallel to said plane of movement of said drive means, said drive means and said toggle means being interengaged for operating the latter means upon movement of the former means, and means interengaging said toggle means and said member for moving said member upon the operation of said toggle means, said toggle means comprising a crank lever pivotally mounted at one end thereof on said plate and a longitudinally extending arm pivoted to the other end of said crank lever to form a toggle joint at said other end, said plate being provided with a slotted offset portion in which the free end of said arm is slidably movable, and spring means carried by said arm between said toggle joint and said offset portion, said lever having a laterally offset part engaged in said drive means for operating said toggle.

4. In a switch casing having an operable cover and provided with an operating handle mounted for movement on said cover and having a member movably mounted in said casing for actuating a switch disposed within the casing, mechanism operable by said handle for moving said member comprising a plate fixedly mounted in said casing, said plate being mounted on the rear wall of said casing and extending toward said cover in substantially parallel disposition with the side walls of said casing, drive means operatively connected to said handle and mounted for pivotal movement on said plate in a plane transverse the path of movement of said member, toggle means mounted on said plate for movement in opposite directions in a plane parallel to said plane of movement of said drive means, said drive means and said toggle means being interengaged for operating the latter means upon movement of the former means, and means interengaging said toggle means and said member for moving said member upon the operation of said toggle means, said toggle means comprising a crank lever pivotally mounted at one end thereof on said plate and a longitudinally extending arm pivoted to the other end of said crank lever to form a toggle joint at said other end, said plate being provided with a slotted oifset portion in which the free end of said arm is slidably movable, and spring means carried by said arm between said toggle joint and said offset portion, said crank lever having a laterally ofiset part engaged in said drive means for operating said toggle and being provided with a slotted portion for receiving a laterally offset part of said switch-actuating member for moving the latter.

5. In an openable switch casing provided with an operating handle mounted for movement thereon externally of the casing and having a member movably mounted therein for actuating a switch disposed within the casing, mechanism operable by said handle for moving said member comprising a plate fixedly mounted in said casing, said plate being mounted on the rear wall of said casing and extending toward said cover in substantially parallel disposition with the side walls of said casing, drive means operatively connected to said handle and mounted for pivotal movement on said plate, toggle means mounted on said plate for movement in opposite directions, said drive means and said toggle means being interengaged for operating the latter means upon movement of the former means, and means interengaging said toggle means and said member for moving said member upon the operation of said toggle means, said drive means being provided with spaced axially extending portions, and lever means operatively connected to said handle and positioned between said axially extending portions for pivotally moving said drive means, at least one of said axially extending portions being provided with a part forming a pocket adapted to receive a tool in the open condition of said casing for actuating said mechanism.

6. In a switch casing having an operable cover and provided with an operating handle mounted for movement on said cover and having a member movably mounted in said casing for actuating a switch disposed within the casing, mechanism operable by said handle for moving said member comprising a plate fixedly mounted in said casing, said plate being mounted on the rear wall of said casing and extending toward said cover in substantially parallel disposition with the side walls of said casing, drive means operatively connected to said handle and mounted for pivotal movement on said plate, toggle means mounted on said plate for movement in opposite directions, said drive means and said toggle means being interengaged for operating the latter means upon movement of the former means, and means interengaging said toggle means and said member for moving said member upon the operation of said toggle means, said plate being provided with a peripheral portion having spaced detent means, said drive means having a laterally extending part overlying said peripheral portion and engageable by said detent means for limiting said movement of said drive means.

7. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and off positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, said actuator means having a portion spaced from said cover, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed between said actuator portion and said cover to intercept said actuator portion to prevent opening of said cover in said ofF position of the handle, and said handle having a position within the range of said oif" position thereof wherein said actuator portion is clear of said latch member to allow the cover to open.

8. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and off positions for closing and opening said switch means, an operating handle on said cover movable between on" and Off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, said actuator means having an extension substantially parallel with said cover and spaced therefrom, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed between said aetuator extension and said cover to intercept said extension to prevent opening of said cover in said off position of the handle, and said handle having a position within the range of said off position thereof wherein said actuator extension is clear of said latch member to allow the cover to open.

9. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and off positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on" position of said handle, said actuator means having an extension substantially parallel with said cover and spaced therefrom, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed between said actuator extension and said cover to intercept said extension to prevent opening of said cover in said 01f position of the handle, and said handle having a position within the range of said off position thereof wherein said actuator extension is clear of said latch member to allow the cover to open, said switch operating mechanism comprising toggle means for opening and closing said switch means with a snap action, and said movable part being a toggle member.

10. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and olf positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, said actuator means having an extension substantially parallel with said cover and spaced therefrom, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off" position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed between said actuator extension and said cover to intercept said extension to prevent opening of said cover in said off position of the handle, and said handle having a position within the range of said position thereof wherein said actuator extension is clear of said latch member to allow the cover to open, said switch operating mechanism comprising a plate mounted within said enclosure and toggle means mounted on said plate for opening and closing said switch means with a snap action, and said latch member being mounted for pivotal movement on said plate.

11. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and o positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, said actuator means having an extension substantially parallel with said cover and spaced therefrom, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed between said actuator extension and said cover to intercept said extension to prevent opening of said cover in said off position of the handle, and said handle having a position within the range of said off position thereof wherein said actuator extension is clear of said latch member to allow the cover to open, said switch operating mechanism comprising a plate mounted within said enclosure and toggle means mounted on said plate for opening and closing said switch means with a snap action, said latch memher being mounted for pivotal movement on said plate, and said movable part being a toggle member.

12. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and off positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, said actuator means having an extension substantially parallel with said cover and spaced therefrom, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed between said actuator extension and said cover to intercept said extension to prevent opening of said cover in said 0 position of the handle, and said handle having a position within the range of said off position thereof wherein said actuator extension is clear of said latch member to allow the cover to open, said latch member being provided with oppositely projecting wings at a free end thereof for intercepting said locking member and said extension in the on and o positions, respectively, of said handle.

13. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and off positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the on position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the ofli position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed to intercept said actuator to prevent opening of said cover in said off position of the handle, and said handle having a position within the range of said off position thereof wherein said actuator is clear of said latch member to allow the cover to open, said locking member being movable relative to said cover, and means operable externally of said cover for moving said locking member to a position wherein it clears said latch member, whereby to open said cover in the on position of said handle.

14. In an enclosed switch comprising switch means mounted within an enclosure provided with an openable cover, switch operating mechanism within said enclosure operable to on and off positions for closing and opening said switch means, an operating handle on said cover movable between on and off positions thereof, actuator means for said switch operating mechanism operatively connected to said handle for operation thereby, said actuator means being carried by said cover interiorly thereof, a locking member carried by said cover interiorly thereof, a latch member mounted within said enclosure for movement between projected and retracted positions thereof, means normally biasing said latch member in the *on" position of said handle to said projected position wherein said latch member is disposed to intercept said locking element to prevent the opening of said cover in said on position of said handle, and said switch operating mechanism being provided with a movable part which is operable upon actuation of said mechanism to the off position thereof to move said latch against said bias thereof to its retracted position wherein said latch is disposed to intercept said actuator to prevent opening of said cover in said off position of the handle, and said handle having a position within the range of said off position thereof wherein said actuator is clear of said latch member to allow the cover to open, and means for locking said handle in said on and off positions, respectively, whereby, when locked in the latter position, said handle is secured against movement to its position for opening the cover for positively locking the cover in said off position, and when locked in said on" position, said handle is secured against movement for operating the switch.

15. In a switch casing provided with an openable cover, a handle mounted on the cover for pivotal movement thereon externally of the casing through a predetermined arcuate range between off and on positions, respectively, an operating lever pivotally mounted on the inner surface of said cover for operating a switch disposed within the casing under the control of the handle, a floating link interconnecting said handle and lever to transmit the movement of said handle through its arcuate range into a smaller movement of said operating lever through a substantially linear range, a pivoted drive lever mounted within said casing, said drive lever being ongaged by said operating lever in the closed condition of the cover for movement of said drive lever through a predetermined range, over-centered spring toggle means within said casing and said toggle means having a range of movement substantially greater than said drive lever, a switch operating member operatively connected to said toggle means for operation by said toggle means through the range of movement of said toggle means, and said toggle means having a lost motion connection with said drive lever whereby the operation of said drive lever through its range of movement overcenters the toggle means for movement through the larger range thereof.

16. In a switch casing provided with an openable cover, a handle mounted on the cover for pivotal movement thereon externally of the casing through a predetermined arcuate range between otf and on" positions, respectively, an operating lever pivotally mounted on the inner surface of said cover for operating a switch disposed within the casing under the control of the handle, a [loating link interconnecting said handle and lever to transmit the movement of said handle through its arcuate range into a smaller movement of said operating lever through a substantially linear range, a pivoted drive lever mounted within said casing, said drive lever being engaged by said operating lever in the closed condition of the cover for movement of said drive lever through a predetermined range, overcentered spring toggle means within said casing and said toggle means having a range of movement substantially greater than said drive lever, a switch operating member operatively connected to said toggle means for operation by said toggle means through the range of movement of said toggle means, and said tooggle means having a lost motion connection with said drive lever whereby the operation of said drive lever through its range of movement overcenters the toggle means for movement through the larger range thereof, said toggle means including a crank lever having a lost motion connection with said drive lever, said crank lever being mounted in spaced pivotal alignment with said drive lever, and said switch operating member being mounted for movement about the pivotal axis of said crank lever.

17. In a switch casing provided with an openable cover, a handle mounted on the cover for pivotal movement thereon externally of the casing through a predetermined arcuate range between off and on positions, respectively, an operating lever pivotally mounted on the inner surface of said cover for operating a switch disposed within the casing under the control of the handle, a floating link interconnecting said handle and lever to transmit the movement of said handle through its arcuate range into a smaller movement of said operating lever through a substantially linear range, a pivoted drive lever mounted within said casing, said drive lever being engaged by said operating lever in the closed condition of the cover for movement of said drive lever through a predetermined range, overcentered spring toggle means within said casing and said toggle means having a range of movement substantially greater than said drive lever, a switch operating member operatively connected to said toggle means for operation by said toggle means through the range of movement of said toggle means, and said toggle means having a lost motion connection with said drive lever whereby the operation of said drive lever through its range of movement overcenters the toggle means for movement through the larger range thereof, said operating lever being pivotally mounted to the cover at one end thereof and having its free end engageable with said drive lever, and said floating link being pivotally connected to said operating lever intermediate the ends of said operating lever.

References Cited in the file of this patent UNITED STATES PATENTS 659,946 Whittingharn Oct. 16, 1900 1,986,221 Sachs Jan. 1, 1935 2,163,230 Rowe June 20, 1939 2,276,006 Samzelius Mar. 10, 1942 2,325,697 Millermaster et al. Aug. 3, 19 13 2,344,636 Quast Mar. 21, 1944 2,381,848 Van Valkenburg Aug. 7, 1945 2,467,307 Hammerly Apr. 12, 1949 2,468,463 Rowe a. Apr. 26, 1949 2,501,742 Rowe Mar. 28, 1950 2,512,505 Rowe June 20. 1950 2,555,331 Grady June 5, 1951 FOREIGN PATENTS 61,276 Switzerland Oct. 8, 1912 

